The burnt shells of vehicles are pictured along Race Course Road following a riot near Singapore's Little India district - Reuters

A 400-strong mob reportedly set fire to a number of vehicles in Singapore after a man was hit and killed by a bus in the country's Little India district.

The rioters also clashed with three busloads of police officers who responded to the rioting on the Race Course Road. At least 18 people were reportedly injured, including security personnel who were dispatched to quell riots.

The mob set fire to three police vehicles, an ambulance, and a motorbike. Several other police, civil defence and privately owned cars were also damaged.

Footage from local television new channels showed several cars on fire and police cars being flipped over, and at least two explosions were heard on the site, according to the Star.

The rioters were seen smashing the windscreen of a bus as the driver remained trapped inside.

Mobs also threw "projectiles" on the rescuers who were trying to take the injured to hospitals, Civil Defence Force (CDF) officials said.

Police have cordoned off Race Course Road and the rioters have dispersed as about 300 officers comb the site.

Singapore's The Straits Times reported that the rioting started when a Bangladeshi worker who was hit by a bus was being taken to hospital.

Little India usually draws a number of workers from Bangladesh and India on Sundays, who generally spend their day off in the district.

The 27 people arrested in connection with rioting are reportedly of South Asian origin. More arrests are expected to be made in the coming days.

Rare Incident

Incidents like this are rare in Singapore given the tough laws on rioting that carry a sentence of up to seven years in prison and possible caning.

The violence fuels concerns about possible rising discontent among the low-paid foreign workers who are mainly engaged in the construction sector.

The island state has a population of about 5.3 million, out of which about 1.3 million are foreign workers. Last year, 170 public bus drivers from mainland China went on an illegal strike, while there have been other cases of protests by low-pay unskilled workers in recent years.

Singaporean authorities have always strived to ensure peaceful co-existence of foreign and local communities.

"By and large, the relationships [between migrant workers and Singaporeans] are good," said Teo Chee Hean, Deputy Prime Minister and Minister of Home Affairs. "We welcome guest workers here who are law-abiding and who want to make a living for themselves."

Little India residents told the WSJ that occasional fights are common among the foreign workers who live here, but rioting on this scale is unusual.

"This is a serious incident which has resulted in injuries and damage to public property," Hean said. "Police will spare no efforts to apprehend the subjects involved in the riot."

This riot is loosely remniscent of the racially charged violence of 1969, between Chinese and Malay residents, which left at least four dead and 80 injured.

Singaporean Police officials said that this was a case of "rioting with dangerous weapons", which is an offence carrying a penalty up to 10 years in jail apart from caning.

"Whatever events may have sparked the rioting, there is no excuse for such violent, destructive, and criminal behaviour. We will spare no effort to identify the culprits and deal with them with the full force of the law", Prime Minister Lee Hsien Loong wrote in a Facebook post.